add directory study

study/linux-travel/MINIX-1.5/1.5/Source/amoeba/util/prot.c

@@ -0,0 +1,78 @@
+#include <stdio.h>
+#include <sys/types.h>
+#include <pwd.h>
+#include <grp.h>
+
+#define isblank(c)	((c) == ' ' || (c) == '\t' || (c) == '\n')
+
+#define MAXTOKEN	16
+
+static char *gettok(fp)
+FILE *fp;
+{
+	static char buf[MAXTOKEN + 1];
+	register char c, *p = buf;
+
+	do		/* skip blanks */
+		if ((c = getc(fp)) == EOF)
+			return(0);
+	while (isblank(c));
+	do {
+		if (c == '#') {		/* skip comment */
+			while ((c = getc(fp)) != EOF)
+				if (c == '\n') break;
+			break;
+		}
+		*p++ = c;
+	} while (c != ':' && (c = getc(fp)) != EOF && !isblank(c));
+	*p++ = 0;
+	return(buf);
+}
+
+static number(p)
+char *p;
+{
+	int n;
+
+	return sscanf(p, "%d", &n) == 1 ? n : -1;
+}
+
+chkprot(chkfil, chkdefault, uid, gid)
+char *chkfil;
+char *chkdefault;
+{
+	register userchk = 0, n;
+	register FILE *fp;
+	register char *p;
+	register struct passwd *pw;
+	register struct group *gr;
+	extern FILE *fopen();
+	extern struct passwd *getpwuid();
+	extern struct group *getgrgid();
+
+	pw = getpwuid(uid);
+	endpwent();
+	gr = getgrgid(gid);
+	endgrent();
+	if ((fp = fopen(chkfil, "r")) == NULL && (fp = fopen(chkdefault, "r")) == NULL)
+		return(-1);
+	while ((p = gettok(fp)) != 0)
+		if (strcmp(p, "group:") == 0)
+			userchk = 0;
+		else if (strcmp(p, "user:") == 0)
+			userchk = 1;
+		else if (userchk) {
+			if (pw && strcmp(p, pw->pw_name) == 0 ||
+							uid == number(p)) {
+				fclose(fp);
+				return(1);
+			}
+		}
+		else
+			if (gr && strcmp(p, gr->gr_name) == 0 ||
+							gid == number(p)) {
+				fclose(fp);
+				return(1);
+			}
+	return(0);
+}